Every word is sweet and every grain is hard. "Wine in a glass, Chinese food on a plate" comes from a catering couplet. You can break a sentence into several phrases, oppose them respectively, and finally combine them into a sentence. The next sentence is "every word is sweet, but every grain is hard". Couplets, one of the traditional cultures in China, also called couplets or couplets, are antithetical sentences written on paper, cloth or engraved on bamboo, wood and columns.